Long live QRawFont!

The QGlyphs API was initially attempted with a bastardization of
QFont which was meant to encapsulate a single, physical font
instance (a QFontEngine) where a set of glyph indexes would make
sense. This is not how QFont was intended to be used, and it caused
several issues. At the same time, the requirement for loading a
font from ttf/otf data and be able to access it and use it without
polluting the rest of the process with the font arose. To support
these two APIs we introduce QRawFont, which is an abstraction on
top of a single physical font.

Done-with: Jiang Jiang

1 files changed, 24 insertions, 30 deletions

diff --git a/src/gui/text/qfontenginedirectwrite.cpp b/src/gui/text/qfontenginedirectwrite.cpp
index af5bab2ffe..f0a3644865 100644
--- a/src/gui/text/qfontenginedirectwrite.cpp
+++ b/src/gui/text/qfontenginedirectwrite.cpp
@@ -170,17 +170,12 @@ namespace {
 
 }
 
-QFontEngineDirectWrite::QFontEngineDirectWrite(const QString &name,
-                                               IDWriteFactory *directWriteFactory,
-                                               IDWriteGdiInterop *directWriteGdiInterop,
-                                               IDWriteFont *directWriteFont,
+QFontEngineDirectWrite::QFontEngineDirectWrite(IDWriteFactory *directWriteFactory,
+                                               IDWriteFontFace *directWriteFontFace,
                                                qreal pixelSize)
-    : m_name(name)
-    , m_directWriteFont(directWriteFont)
-    , m_directWriteFontFace(0)
+    : m_directWriteFontFace(directWriteFontFace)
     , m_directWriteFactory(directWriteFactory)
     , m_directWriteBitmapRenderTarget(0)
-    , m_directWriteGdiInterop(directWriteGdiInterop)
     , m_lineThickness(-1)
     , m_unitsPerEm(-1)
     , m_ascent(-1)
@@ -188,24 +183,17 @@ QFontEngineDirectWrite::QFontEngineDirectWrite(const QString &name,
     , m_xHeight(-1)
     , m_lineGap(-1)
 {
-    m_directWriteFont->AddRef();
     m_directWriteFactory->AddRef();
-    m_directWriteGdiInterop->AddRef();
+    m_directWriteFontFace->AddRef();
 
     fontDef.pixelSize = pixelSize;
-
-    HRESULT hr = m_directWriteFont->CreateFontFace(&m_directWriteFontFace);
-    if (FAILED(hr))
-        qErrnoWarning("QFontEngineDirectWrite: CreateFontFace failed");
-
     collectMetrics();
 }
 
 QFontEngineDirectWrite::~QFontEngineDirectWrite()
 {
-    m_directWriteFont->Release();
     m_directWriteFactory->Release();
-    m_directWriteGdiInterop->Release();
+    m_directWriteFontFace->Release();
 
     if (m_directWriteBitmapRenderTarget != 0)
         m_directWriteBitmapRenderTarget->Release();
@@ -213,10 +201,10 @@ QFontEngineDirectWrite::~QFontEngineDirectWrite()
 
 void QFontEngineDirectWrite::collectMetrics()
 {
-    if (m_directWriteFont != 0) {
+    if (m_directWriteFontFace != 0) {
         DWRITE_FONT_METRICS metrics;
 
-        m_directWriteFont->GetMetrics(&metrics);
+        m_directWriteFontFace->GetMetrics(&metrics);
         m_unitsPerEm = metrics.designUnitsPerEm;
 
         m_lineThickness = DESIGN_TO_LOGICAL(metrics.underlineThickness);
@@ -616,19 +604,25 @@ const char *QFontEngineDirectWrite::name() const
 
 bool QFontEngineDirectWrite::canRender(const QChar *string, int len)
 {
-    for (int i=0; i<len; ++i) {
-        BOOL exists;
-        UINT32 codePoint = getChar(string, i, len);
-        HRESULT hr = m_directWriteFont->HasCharacter(codePoint, &exists);
-        if (FAILED(hr)) {
-            qErrnoWarning("QFontEngineDirectWrite::canRender: HasCharacter failed");
-            return false;
-        } else if (!exists) {
-            return false;
+    QVarLengthArray<UINT32> codePoints(len);
+    int actualLength = 0;
+    for (int i=0; i<len; ++i, actualLength++)
+        codePoints[actualLength] = getChar(string, i, len);
+
+    QVarLengthArray<UINT16> glyphIndices(actualLength);
+    HRESULT hr = m_directWriteFontFace->GetGlyphIndices(codePoints.data(), actualLength,
+                                                        glyphIndices.data());
+    if (FAILED(hr)) {
+        qErrnoWarning(hr, "QFontEngineDirectWrite::canRender: GetGlyphIndices failed");
+        return false;
+    } else {
+        for (int i=0; i<glyphIndices.size(); ++i) {
+            if (glyphIndices.at(i) == 0)
+                return false;
         }
-    }
 
-    return true;
+        return true;
+    }
 }
 
 QFontEngine::Type QFontEngineDirectWrite::type() const